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Current status and future directions of the Tibetan Plateau ecosystem research

Science Bulletin 2019年第7期64卷 428-430页

作者： Yangjian Zhang Yixuan Zhu Junxiang Li Yao Chen Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences

The Tibetan Plateau (TP) encompasses Xizang and Qinghai and parts of northern Yunnan and Sichuan provinces, with a total area of circa 2.6 millions km2. The 2013 satellite data showed that grasslands, forests, wetlands, agricultural lands, and deserts account for 60%, 7.7%, 1.4%, 0.3%, and 30%, respectively, of total TP land (1)Due to its existence in dry, high altitude and cold environments, the TP ecosystem is extremely vulnerable to global climate change and studies on the TP ecosystem can be utilized as a pre-warning for other ecosystems.

关键词： Current status and future directions of the Tibetan Plateau ecosystem research TP

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What is the mass of loess in the Loess Plateau of China?

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Science Bulletin 2019年第8期64卷 534-539页

作者： Yuanjun Zhu Xiaoxu Jia Jiangbo Qiao Ming'an Shao State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University Institute of Soil and Water Conservation Chinese Academy of Sciences & Ministry of Water Resources College of Resources and Environment University of Chinese Academy of Sciences Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

The Loess Plateau of China(LP) has the largest and thickest loess deposits in the world. Quantifying the amount of loess in the LP is crucial for investigating the accumulation and erosion of loess, and determining the regional soil and water resource capacity. We used loess thickness data, a pedotransfer function for bulk density(BD), and the clay content data observed in 242 sites across the LP to derive the BD of loess and then estimate the loess mass and its distribution across the LP. The results indicated that the average BD of loess between the surface and bedrock is 1.58 g cm^(-3), varying from 1.18 to 1.87 g cm^(-3).The total loess mass is approximately 5.45 ? 10^(13) t, and the average loess mass over an area of 1 m^2 is 169 t, ranging from 1.36 to 585 t. The greatest mass of loess is in the south-central of the LP while the lowest mass of loess is in the northwest and river valley areas. Our estimate of loess mass provides key data for calculating water, carbon, and nutrient storages in the LP, which improves our understanding of soil-water processes and ecohydrological systems in this landscape.

关键词： The Loess Plateau Loess mass Pedotransfer function Soil erosion Bulk density

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Vertical distribution and storage of soil organic and inorganic carbon in a typical inland river basin,Northwest China

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Journal of Arid Land 2018年第2期10卷 183-201页

作者： YANG Fan HUANG Laiming YANG Renmin YANG Fei LI Decheng ZHAO Yuguo YANG Jinling LIU Feng ZHANG Ganlin State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Knowledge of soil carbon（C） distribution and its relationship with the environment can improve our understanding of its biogeochemical cycling and help to establish sound regional models of C cycling. However, such knowledge is limited in environments with complex landscape configurations. In this study, we investigated the vertical distribution and storage of soil organic carbon（SOC） and soil inorganic carbon（SIC） in the 10 representative landscapes（alpine meadow, subalpine shrub and meadow, mountain grassland, mountain forest, typical steppe, desert steppe, Hexi Corridor oases cropland, Ruoshui River delta desert, Alxa Gobi desert, and sandy desert） with contrasting bioclimatic regimes in the Heihe River Basin, Northwest China. We also measured the 87 Sr/86 Sr ratio in soil carbonate to understand the sources of SIC because the ratio can be used as a proxy in calculating the contribution of pedogenic inorganic carbon（PIC） to total SIC. Our results showed that SOC contents generally decreased with increasing soil depth in all landscapes, while SIC contents exhibited more complicated variations along soil profiles in relation to pedogenic processes and parent materials at the various landscapes. There were significant differences of C stocks in the top meter among different landscapes, with SOC storage ranging from 0.82 kg C/m^2 in sandy desert to 50.48 kg C/m^2 in mountain forest and SIC storage ranging from 0.19 kg C/m^2 in alpine meadow to 21.91 kg C/m^2 in desert steppe. SIC contributed more than 75% of total C pool when SOC storage was lower than 10 kg C/m^2, and the proportion of PIC to SIC was greater than 70% as calculated from Sr isotopic ratio, suggesting the critical role of PIC in the C budget of this region. The considerable variations of SOC and SIC in different landscapes were attributed to different pedogenic environments resulted from contrasting climatic regimes, parent materials and vegetation types. This study provides an evidence for a general t

关键词： Heihe River Basin arid ecosystem soil landscape pedogenesis pedogenic carbonate SOC CaCO3

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Seasonal patterns of root and shoot interactions in an alpine meadow on the Tibetan Plateau

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Journal of Plant Ecology 2012年第2期5卷 182-190页

作者： Minghua Song Qiwu Hu Yuqiang Tian Hua Ouyang Key Laboratory of Ecosystem Network Observation and Modelling Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101People’s Republic of China

Aims Numerous studies have showed that the balance between negative and positive plant–plant interactions shifted along environmental *** little is known how the positive or negative plant–plant interactions varied with temporal fluctuating habitat conditions and plant ontogenetic *** In a 2-year experiment,the four perennial grasses(Kobresia humilis,Stipa aliena,Elymus nutans and Saussurea superba)were grown under four interaction treatments(no root or shoot interaction,only shoot interaction,only root interaction,root and shoot interaction).Intensity of above-and belowground interactions is proposed to vary with the fluctuation of seasonal climatic conditions and soil available *** we report measurements of above-and belowground interactions during entire growing *** between plant interaction intensity and seasonal soil available N as well as habitat climate conditions was also *** findings Our experiment found that root interactions had negative effect on plant growth for the four species during growing ***,both negative and positive shoot interactions occurred among the four *** there being shoot facilitative effect for *** and ***,the full interaction was negative,suggested that root interaction take more important role on plant growth than that of shoot *** interaction between root and shoot effect varied as a function of species identity and growth *** weak correlation of plant interaction intensity to habitat environmental factors suggested that plant ontogenetic characteristics may be primary factors causing temporal variation in plant interaction.

关键词： competition facilitation growing season ontogenetic phase habitat environmental conditions

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Spatio-temporal patterns of temperature extremes and their response to atmospheric circulation factors in China from 1961 to 2020

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Journal of Geographical Sciences 2024年第10期34卷 1883-1903页

作者： LUO Yuanbo ZHOU Yuke ZHOU Chenghu State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCAsBeijing 100101China

Changes in surface temperature extremes have become a global *** on the daily lowest temperature(TN)and daily highest temperature(TX)data from 2138weather stations in China from 1961 to 2020,we calculated 14 extreme temperature indices to analyze the characteristics of extreme temperature *** widespread changes observed in all extreme temperature indices suggest that China experienced significant warming during this ***,the cold extreme indices,such as cold nights,cold days,frost days,icing days,and the cold spell duration index,decreased significantly by-6.64,-2.67,-2.96,-0.97,and-1.01 days/decade,*** contrast,we observed significant increases in warm extreme *** number of warm nights,warm days,summer days,tropical nights,and warm spell duration index increased by 8.44,5.18,2.81,2.50,and 1.66d/decade,*** addition,the lowest TN,highest TN,lowest TX,and highest TX over the entire period rose by 0.47,0.22,0.26,and 0.16℃/decade,***,using Pearson's correlation and wavelet coherence analyses,this study identified a strong association between extreme temperature indices and atmospheric circulation factors,with varying correlation strengths and resonance periods across different time-frequency domains.

关键词： temperature changes global warming atmospheric circulation wavelet coherence analysis China

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Characteristics of Dried Soil Layers Under Apple Orchards of Different Ages and Their Applications in Soil Water Managements on the Loess Plateau of China

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Pedosphere 2015年第4期25卷 546-554页

作者： WANG Yunqiang SHAO Mingan LIU Zhipeng ZHANG Chencheng State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences & Ministry of Water Resources Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences

Negative soil water balance （i.e., water input 〈 water output） can lead to soil desiccation and subsequently the occurrence of a dried soil layer （DSL）. The DSLs are generally studied at a specific sampling depth （e.g., 500 cm）, and the actual extent of DSLs remains unknown due to the challenge of collecting deep soil samples. To investigate the characteristics of actual DSLs under different ages of apple orchards and ascertain the optimal age of apple orchards for avoiding/controlling the formation of DSLs, soil samples were collected to a depth of 1800 cm under apple orchards of different ages in Changwu on the Loess Plateau of China. As the ages increased, soil water content （SWC） and mean SWC in DSLs showed an overall decreasing trend, whereas while DSL thickness and the quantity of water deficit （QWD） in DSLs demonstrated an increasing trend. The DSL was the thickest （1 600 cm） under the 17-yeax-old orchard, the forming velocity of DSL thickness was the highest at the apple tree growth stage of 9-17 years （168 cm year-l）, and the highest increasing velocity of QWD （-181 mm year-1） was also observed at this stage. The thickness of DSL was significantly correlated with growth age and root depth of apple trees （r 〉 0.88）, whereas the QWD and mean SWC in DSLs were found to have no correlation with them. The optimal age of apple orchards for avoiding/controlling the formation of DSLs was about 9 years. This information provided pertinent references for the management of deep water resources by controlling the growth age of plants. key Words： deep soil, growth age, plant roots, soil desiccation, soil water content, soil-plant water relation.

关键词： deep soil growth age plant roots soil desiccation soil water content soil-plant water relation

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Changes in individual plant traits and biomass allocation in alpine meadow with elevation variation on the Qinghai-Tibetan Plateau

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Science China(Life Sciences) 2010年第9期53卷 1142-1151页

作者： MA WeiLing SHI PeiLi LI WenHua HE YongTao ZHANG XianZhou SHEN ZhenXi CHAI SiYue Lhasa National Ecological Research Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Graduate University of Chinese Academy of Sciences Beijing 100049China

Plant traits and individual plant biomass allocation of 57 perennial herbaceous species,belonging to three common functional groups (forbs,grasses and sedges) at subalpine (3700 m ASL),alpine (4300 m ASL) and subnival (≥5000 m ASL) sites were examined to test the hypothesis that at high altitudes,plants reduce the proportion of aboveground parts and allocate more biomass to belowground parts,especially storage organs,as altitude increases,so as to geminate and resist environmental ***,results indicate that some divergence in biomass allocation exists among *** increasing altitude,the mean fractions of total biomass allocated to aboveground parts *** mean fractions of total biomass allocation to storage organs at the subalpine site (7%±2% S.E.) were distinct from those at the alpine (23%±6%) and subnival (21%±6%) sites,while the proportions of green leaves at all altitudes remained almost *** 4300 m and 5000 m,the mean fractions of flower stems decreased by 45% and 41%,respectively,while fine roots increased by 86% and 102%,*** leaf areas and leaf areas of forbs and grasses deceased with rising elevation,while sedges showed opposite *** all three functional groups,leaf area ratio and leaf area root mass ratio decreased,while fine root biomass increased at higher *** allocation patterns of alpine plants were characterized by a reduction in aboveground reproductive organs and enlargement of fine roots,while the proportion of leaves remained *** was beneficial for high altitude plants to compensate carbon gain and nutrient uptake under low temperature and limited nutrients by stabilizing biomass investment to photosynthetic structures and increasing the absorption surface area of fine *** contrast to forbs and grasses that had high mycorrhizal infection,sedges had higher single leaf area and more root fraction,especially fine roots.

关键词： Qinghai-Tibetan Plateau climate stress biomass allocation shoot/root ratio plant traits fine roots

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Different responses of soil respiration and its components to nitrogen and phosphorus addition in a subtropical secondary forest

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Forest ecosystems 2021年第3期8卷 491-503页

作者： Junjun Zhang Yong Li Jinsong Wang Weinan Chen Dashuan Tian Shuli Niu Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Beijing Key Laboratory of Wetland Services and Restoration Institute of Wetland ResearchChinese Academy of ForestryBeijing 100091China Department of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Background:Nitrogen(N)and phosphorus(P)deposition have largely affected soil respiration(Rs)in forest ***,few studies have explored how N and P individually or in combination to influence Rs and its components(autotrophic respiration,Ra;heterotrophic respiration,Rh),especially in highly P-limited subtropical *** address this question,we conducted a field manipulation experiment with N and/or P addition in a 50-year-old subtropical secondary ***:We found that N addition on average reduced Rs,Ra,and Rh by 15.2%,15%,and 11.7%,respectively during 2-year field study.P addition had an inconsistent effect on Ra,with Ra increasing by 50.5%in the first year but reducing by 26.6%in the second ***,P addition on average decreased Rh by 8.9%–30.9%and Rs by 6.7%–15.6%across 2 *** contrast,N and P co-addition on average increased Rs,Ra,and Rh by 1.9%,7.9%,and 2.1%during the experimental *** Rs and Rh were significantly correlated with soil temperature,their temperature sensitivities were not significantly changed by *** was predominantly regulated by soil nitrogen availability(NH4+and NO3−),soil dissolved organic carbon(DOC),and enzyme activities,while the variation in Rh was mainly attributable to changes in soil microbial community composition and soilβ-D-Cellubiosidase(CB)andβ-Xylosidase(XYL)***:Our findings highlight the contrasting responses of Rs and its components to N or P addition against N and P co-addition,which should be differentially considered in biogeochemical models in order to improve prediction of forest carbon dynamics in the context of N and P enrichment in terrestrial ecosystems.

关键词： Nitrogen deposition Phosphorus enrichment Heterotrophic respiration Autotrophic respiration Enzyme activities Microbial community composition

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Construction and progress of Chinese terrestrial ecosystem carbon, nitrogen and water fluxes coordinated observation

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Journal of Geographical Sciences 2016年第7期26卷 803-826页

作者：于贵瑞任伟陈智张雷明王秋凤温学发何念鹏张黎方华军朱先进高扬孙晓敏 Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research CAS University of Chinese Academy of Sciences

Eddy Covariance technique(EC) achieves the direct measurement on ecosystem carbon, nitrogen and water fluxes, and it provides scientific data for accurately assessing ecosystem functions in mitigating global climate change. This paper briefly reviewed the construction and development of Chinese terrestrial ecosystem flux observation and research network(China FLUX), and systematically introduced the design principle and technology of the terrestrial ecosystem carbon, nitrogen and water fluxes coordinated observation system of China FLUX. In addition, this paper summarized the main progress of China FLUX in the ecosystem carbon, nitrogen and water exchange and environmental controlling mechanisms, the spatial pattern of carbon, nitrogen and water fluxes and biogeographical mechanisms, and the regional terrestrial ecosystem carbon budget assessment. Finally, the prospects and emphases of the terrestrial ecosystem carbon, nitrogen and water fluxes coordinated observation of China FLUX are put forward to provide theoretical references for the development of flux observation and research in China.

关键词： eddy covariance technique carbon-water-nitrogen fluxes coupling cycle coordinated observation China FLUX

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Spatial variability of soil water content and related factors across the Hexi Corridor of China

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Journal of Arid Land 2019年第1期11卷 123-134页

作者： LI Xiangdong SHAO Ming'an ZHAO Chunlei JIA Xiaoxu State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water Resources College of Natural Resources and Environment University of Chinese Academy of Sciences Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Soil water content(SWC) is a key factor limiting ecosystem sustainability in arid and semi-arid areas of the Hexi Corridor of China, which is characterized by an ecological environment that is vulnerable to climate change. However, there is a knowledge gap regarding the large-scale spatial distribution of SWC in this region. The specific objectives of this study were to determine the spatial distribution patterns of SWC across the Hexi Corridor and identify the factors responsible for spatial variation of SWC at a regional scale. This study collected and analyzed SWC in the 0–100 cm soil profile from 109 field sampling sites(farmland, grassland and forestland) across the Hexi Corridor in 2017. We selected 17 factors, including land use, topography(latitude, longitude, elevation, slope gradient, and slope aspect), soil properties(soil clay content, soil silt content, soil bulk density, saturated hydraulic conductivity, field capacity, and soil organic carbon content), climate factors(mean annual precipitation, potential evaporation, and aridity index), plant characteristic(vegetation coverage) and planting pattern(irrigation or rain-fed), as possible environmental variables to analyze their effects on SWC. The results showed that SWC was 0.083(±0.067) g/g in the 0–100 cm soil profile and decreased in the order of farmland, grassland and forestland. The SWC in the upper soil layers(0–20, 20–40 and 40–60 cm) had obvious difference when the mean annual precipitation differed by 200 mm. The SWC decreased from southeast to northwest following the same pattern as precipitation, and had a moderate to strong spatial dependence in a large effective range(75–378 km). The SWC showed a similar distribution and had no significant difference between soil layers in the 0–100 cm soil profile. The principal component analysis showed that the mean annual precipitation, geographical position(longitude and latitude) and soil properties(soil bulk density and soil clay content) were the m

关键词： soil water content spatial variability geostatistical analysis soil clay content Hexi Corridor

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